Platform



June 6, 1950 E. A. BLACK 2,510,059

PLATFORM F iled May 16, 1945 FIG. 3.

37A 45 35 3 43 L 47 g I l 1/ J II I'I4 H Y\ i E;\ {m z 27 r k. w, I t i 25 29 i 2| g as FIG.2.

47 T L T a v I 3 37A 375 H INVENTOR.

' ERIC A. BLACK 33 Y 7 5O MAME/mu.

4 21 ATTORNEY Patented June 6, 1950 PLATFORM Eric A. Black, Red Bank, N. .l., assignor to the United States of America as represented by the Secretary of War Application May 16, 1945, Serial No. 594,145

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3'70 0. G. 757) 6 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The present invention relates to improvements in platform and particularly platforms on relatively tall structures which are to be kept parallel to the ground at all times despite lateral movements of the structures.

In positioning certain radar, radio, meteorological and optical apparatus and the like on tall structures such as towers, it is frequently desirable that the apparatus be maintained level with the ground at all times. It has been found that even slight angular variations from the horizontal, due to wind and other causes, particularly as the structures loosen up with time, seriously upset the operating characteristics of such apparatus.

Hence, it is an object of the present invention to provide a simple means for maintaining such platforms exactly horizontal, irrespective of lateral movements of the structure itself.

It is a further object to provide such a means which will allow a platform to be readily adjusted to a level position and which will there after maintain such adjustment.

In general, the present invention resides in supporting a platform on a structure, by means of a universal joint, and then securing said platform to the ground by one or more pairs of parallel, guy-like, levelling rods of equal length, so that the platform and the ground and each pair of guys forms a parallelogram. Then, no matter how much the tower may lean due to the wind or other causes, the platform itself will always remain parallel to the ground.

Although it will be understood that the present invention may be incorporated into a large variety of embodiments, a preferred simple embodiment to illustrate the invention is shown in the annexed drawings, wherein Figure 1 is an elevational view of a tower and platform sustaining a directive antenna, the tower being shown in its normal, laterally undeflected As shown in the drawings, a rectangular tower ll, sustained on a horizontally disposed concrete base l2, comprises four uprights I 3, a plurality of horizontally disposed chords l and a plurality of diagonal braces l1. Spanning the upper ends of two of the diagonally opposite uprights i3 is a horizontally disposed, T section, metal girder 55, the central Web of the T extending downwardly. Spanning the other two uprights It, also horizontally disposed, and normal to girder I9, is a second, T section, metal girder 2|, which is separated at its center, into the girder segments Zia, Zlb, to make room for the girder i9. Said girder sections 2m, 25b are joined together by an elongated metal roller member 25, which is flat on the bottom and half oval on top and crosses the center of the girder l9 and is securely welded to the upper surfaces of the girder sections 21a, Mb.

The midpoint of the half oval surface of the roller member 25 is provided with an upwardly extending metal pivot dowel 2? which, in cross section, is shaped like an upwardly extending gear tooth. Resting upon said half oval roller member 25 is a flat circular metal disk 29. Said disk 29 is provided at the center of its lower face with a pivot hole receivable to the pivot dowel 2i, and shaped, in cross section, like a geartooth space so that said dowel 27 may pivot in said hole to allow the said disk 29 to roll on the half oval roller member 25. Extending upwardly from the center of the disk 29 is a second pivot dowel 31 similar to the pivot dowel 2'! already described.

A platform 33 is pivotally sustained upon the pivot dowel 3! as Will hereinafter appear. Said platform 33 comprises a horizontally disposed, T section, metal girder 35, the central web of the T extending upwardly, and a similar second girder 3?, also horizontally disposed, and normal to the girder 35. Said second girder 31 is separated at its center, into the girder segments 31a, 37b, to make room for the girder 35. The girder segments 37a, t'lb are joined together by a second half oval metal roller member llwhich has its curved surface facing downwardly and which passes under the girder and is securely welded to the lower surfaces of the girder sections 31a, 31b. The central point of the lower curved surface of the roller member All is provided with a pivot hole, receivable to the pivot dowel 3i and shaped, in cross section, like a gear tooth space so as to allow the upper surface of the disk 29 to roll upon said roller member ll.

Resting upon the crossed girders 35, 31 is a platform floor :33 upon which may be positioned any piece of equipment, a directive antenna d5 being shown in the drawings for illustrative purposes.

Passing through vertical holes in the outer extremities of the girders 35, 3'l are four, vertically disposed, elongated, mutually parallel, levelling rods 4-7, which extend from the platform 33 down into the concrete foundation l2 where they are solidly anchored by any suitable anchorage means (not shown). The upper ends of said levelling rods d'l'are screw threaded and each is provided with an adjustingnut efiand a lock nut 50.

In the operation of the apparatus herein described, the nuts 49 are adjusted until all of the levelling rods 4'! are taut and the platform 33 is perfectly level in all directions. The lock nuts 50 are then tightened. It will be seen (Figure 1) that the platform 33 and the foundation !2 are mutually parallel, as are the two levelling rods 47 passing through the'ends of thegir'der 31. Hence, the said platform 33, foundation l2 and two levelling rods il form a, parallelogram. A similar parallelogram is formed between the platform 33, the foundation l2, and the two levt l n re s, w esst i ush th e of the ird n3 a a tly ha n hi u 4% I It,-wi ll thus beseen that the platform 33 will always rernain par le to the foundation 12 defspiteglateral deflections of platform, caused "by the upper end of the tojwer i i l eaning to one side or another A leaning ofthe tower I I to the 'l eii ,Shaw in Fi ure a re th de 2| and the roller member zt, welded thereto, are

je geqfee ee ieheyaa e .ep il an parts being rotated in a clockwise direction. The .disk 29 will slant similarly. However, the platform fli'a, although deflected laterallyto the right, will rernain parallel to the foundation i2, as the rolle r member, H willroll on the disk 29. It will thus be seen that theitworoller members 25,41,

the di sk i9 and thetwo pivot downer-ms forr'na .universal joint which allows the platform 3 to pivot inanydir ection relative to the upper end "ofthe ower l i.

If desired, theconnect'ions between the four ile vlling rods l'land the realisation and the platform 33 maybe of a pivotable type, but, in view 'of'the large length to'thicknessratio' of said levelling lbds fi'kiflwlll De found. that, in practically'all installations, they will flex sufiicientiy id for perfect'opefation, and hence fastening means of the pivotable type "woum be "entirely'superfiu- It willbe understood that, should it be desired to maintain -a platform 'at any angle to a foundar tion other than parallel, this may be effected by arranging'one or more parallelograms so that a line connecting the endsof the levelling rodsfat the foundation will be parallel to thepredeter- ,mined angular position of the platform. Forthis purpose, suitable anchorages which will allow one or more, of the levelling rods to pivot ata point above the level of the foundation must be used.

Since many changes could be made in the above construction and man widely difiere'nt form sustained by said universal joint and parallelto the ground; a plurality of levelling rods, each rod secured at one end to the platform and at the other end to the ground, said rods being parallel to each other and of equal length.

2. A self-levelling platform comprising a horizontally disposed foundation; a tower sustained upon said foundation; an elongated roller member secured to said tower, said elongated roller member being provided with an upwardly facing curved rolling surface, the axis of which surface laterally d eflec table with saidoute V I, levelling rods, each rodbeirig' coupled at one structure and the 'platforrnfsai runs lengthwise of said member; a pivot pin extending upwardly from said curved surface; a disk provided with a hole in its lower surface 'pivotably receivable to said pivot pin; said disk also provided with a second pivot pin extending upwardly from its upper surface; a second elongate'droller'member; said second elongated roller 'membrbeingprovided with a downwardly facing second curved rolling surface, said second rolling surface being provided with a hole pivotably'receivable to said second pivot pin, the axis of saidsecondrolling surface being lengthwise of said second roller member and substantially normal to the axis of the first mentioned curved rolling surface; a platform secured to said second rollenmeniber; 'a 'pliirality, ofjl ell'irig d's; of

to the'foundation andat' tire fother endi'to "the platform, the couplingpointsfbetween the two rods and the foundation "and the "platform ,"Sllbstantially defining the corners, of afpl'ogram, the an gle sofwhich parallelogram arevariable with deflections of the structure, 7

5. A self-levellingplatf" rm for a'str eture or the typewhich hasits lowerfpor f secured to the ground has anu'pper portion which is substantially vertically 'defietable,comprising a platform substantially "level 'with' the ground, a universal joint between said'upper portion of'the joint and 'platform being "defiectable subst iallyjvertic'ally with saidupper portion, twp parallel'rods "of equal length xterlumgirmm; i'e' emanate the platform and coupled at theinoppos'ite ends to said ground and platform "so that said" ground, platform? and rods substantially defiheia parallel- ,ogram during all operational'tfertialdefiectifins of the upper portion of the structure.

dation and t the other endtdfsaid perform; fs'aid foui'idatior'i,- pntrorm and rods "defininga substantial parallelogram. 2

ERIC A. BLACK.

"nnrnlt'niions crrnn The following references "are of ecord inthe file of this-patent: M

" UNITED STATES'PATENTS 'riurnbei: r ame Date 761,219 Goodwin May'31, 1904 2,221,264 Nowick Nov. 12, 1940 

